As shown in FIGS. 1a and 1b LVT flooring usually comprise a transparent wear layer 3 which may be coated by a PU lacquer 2, preferably UV cured, a decorative plastic foil 4 and one or several core layers 5a, 5b which generally are of different density and hardness. Relevant parts of this known description are also a part of the disclosure.
Thin LVT floors with a thickness of 2-3 mm have traditionally been installed by gluing to the sub floor. Recently LVT floors have been introduced on the market that comprises a mechanical locking system, which allows a floating installation without glue. This facilitates installation and eliminates a lot of work to prepare the sub floor for gluing.
Such LVT floors have generally a thickness of 4-5 mm. This thickness is mainly required in order to form the locking system. The panel itself is strong and flexible and a thickness of about 3 mm would in many applications be sufficient but may not be suitable since it's difficult to form a locking system in such thin floors.
Floating LVT floors of this type have however several disadvantages. They are heavy. The density is for example about 1.6 kg/dm3 compared to about 0.8 kg/dm3 for laminate floors. The temperature sensitivity is more than three times higher than for laminate floors.
An LVT floor may move about 2 mm/M when the temperature is changing 20 degrees Celsius.
Such problems related to thickness are also applicable in other high quality floor panels such as wood powder based floors with high density and quality. The additional cost of forming a locking system is considerable since the material content of the whole floor panel has to be increased with 25% or more.